Code:
'random banner code here
'I dont know php so this is just going to be a VB implementation of it
Select Case BannerNumber
Case 1
Open FileOnYourServerBannerNumber1 For Output As #1
    Print #1, "another click"
Close #1
'etc
End Select
like I said I dont know PHP, so this is what you should basicly do, except its in VB.
and instead of using "another click" just add a number 1 or a pipe( | ) then count all of the pipes or whatever when its time to pay or whatever you are doing.